Hawaiian Islands Weather details & Aloha paragraphs / December 17-18, 2012

Air Temperatures – The following maximum temperatures were recorded across the state of Hawaii Monday afternoon:

Lihue, Kauai –                       77  
Honolulu airport, Oahu –         78  
Molokai airport –                    75
Kahului airport, Maui –           80 
Kona airport     –                 82  
Hilo airport, Hawaii –              79

Air Temperatures ranged between these warmest and coolest spots near sea level – and on the highest mountain tops around the state…as of 730pm Monday evening:

Barking Sands, Kauai – 78
Honolulu, Oahu – 72

Haleakala Summit –   M       (near 10,000 feet on Maui)
Mauna Kea Summit – 28      (near 13,800 feet on the Big Island)

Hawaii’s Mountains – Here’s a link to the live web cam on the summit of near 13,800 foot Mauna Kea on the Big Island of Hawaii. This web cam is available during the daylight hours here in the islands…and when there’s a big moon shining down during the night at times. Plus, during the nights you will be able to see stars, and the sunrise and sunset too…depending upon weather conditions. Here's the Haleakala Crater webcam on Maui.

Tropical Cyclone activity in the eastern and central Pacific – Here’s the latest weather information coming out of the National Hurricane Center, covering the eastern north Pacific. You can find the latest tropical cyclone information for the central north Pacific (where Hawaii is located) by clicking on this link to the Central Pacific Hurricane Center. A satellite image, which shows the entire ocean area between Hawaii and the Mexican coast…can be found here.  The 2012 hurricane season is over in the eastern and central Pacific…resuming on May 15th and June 1st 2013.

Aloha Paragraphs

 
 
Clear to partly cloudy, cloudy periods, passing
showers windward sides…some along the
leeward sides here and there too

Gale warning for Alenuihaha, Pailolo
and Kaiwi Channels…and Maalaea Bay

Wind advisory for strong trade winds atop the
Haleakala summit on Maui – and other parts of the
smaller islands from Kauai to the Big Island

The following numbers represent the most recent top wind gusts (mph), along with directions as of Monday evening:

33       Port Allen, Kauai – NE
46       Kahuku Trng, Oahu – ESE
36       Molokai – ENE    
46       Kahoolawe – NE  
61       Kaupo Gap, Maui – NE
36       Lanai – NE
42       South Point, Big Island – NE

Here are the latest 24-hour precipitation totals (inches) for each of the islands as of Monday evening:
 
3.52          Kilohana, Kauai
1.95          Oahu Forest NWR, Oahu
2.80          Molokai
0.11          Kahoolawe
5.74          Puu Kukui, Maui
1.06          Mountain View, Big Island  

We can use the following links to see what’s going on in our area of the north central Pacific Ocean.  Here's the latest NOAA satellite picture – the latest looping satellite image…and finally the latest looping radar image for the Hawaiian Islands.

                                          ~~ Hawaii weather commentary ~~ 

Strong and gusty trade winds will continue to blow across our islands. We currently have a large near 1039 millibar high pressure system (weather map), located to the north of Hawaii this evening. We found strong and gusty winds starting off our day again today. As has been the case during the last week, winds in gusts reached up above the 40 mph mark on many of the islands. This morning before sunrise, there were gusts up above 40 mph on Oahu, Kahoolawe, Maui, Lanai and the Big Island. The strongest of these were reaching 47 mph on at least three of these islands. The other islands in the state were gusting up to just below 40 mph. Now, as we move into the evening hours, we're finding at least a couple of 50+ mph gusts…the strongest of which was 61 mph on Maui!

A high pressure system will be strengthening to near 1040 millibars soon…keeping the trade wind going in the process.  A long lasting wind advisory remains in force over Haleakala summit here on Maui, and covers other parts of Maui County, the Big Island…and parts of all the islands now too. So, look for more windy to very windy weather circumstances continuing through most of the rest of this week. This means more of these 40+ to above 50 mph gusts will exist, across our typically windiest places in the state…at least over the next few days. The longer range outlooks calls for a reduction in our gusty trade winds, perhaps going from the strong to very strong proportions now…back into the moderately strong category by the weekend.

As for precipitation, there will be some, primarily focused along our windward sides, and over the lower mountains on the smaller islands…with a few stretching over into the leeward sides at times too.  The current forecast shows frequent, generally light to moderate showers for our windward sides in the Monday through Wednesday time frame…mostly at night. This will be the result of a remnant cold front or two, or just loosely hung together cloud bands, bringing moisture into the state, on the gusty trade wind flow. Here's a satellite image, showing quite a steady supply of low clouds upstream of our islands, heading towards our windward coasts and slopes. As the winds are so strong now, and will continue in that fashion, some of these showers will be able to travel over into the leeward sides at times too.

At the time of this writing, the wettest place in the state was atop the West Maui Mountains, here on Maui, where a very generous 5.74" has ended up in the rain gauge during the last 24 hours. In sum, blustery trade winds, off and on passing showers windward sections, flying over into the leeward sides at times…most generously at night in both areas. Those leeward sides will have the best chance for sunny weather again on Tuesday, at least on some of the islands, especially Maui and the Big Island in this case. ~~~ One last thing, as I continue to look at the news of the terrible shooting in Connecticut…it remains so utterly heart breaking! Those pictures of the victims and their families, brings tears to my eyes. It's just devastating to realize the damage that has been done there, and to the rest of us everywhere…in a way too. ~~~ I'll be back early Tuesday morning with your next new weather narrative.  I hope you have a good Monday night wherever you're spending it! Aloha for now…Glenn.

World-wide tropical cyclone activity:

Atlantic Ocean/Caribbean Sea:  There are no active tropical cyclones

Gulf of Mexico: There are no active tropical cyclones

Eastern Pacific Ocean: There are no active tropical cyclones

Central Pacific Ocean:  There are no active tropical cyclones

Western Pacific Ocean:  There are no active tropical cyclones

South Pacific Ocean:  Tropical cyclone Evan (04P) remains active in the southwest Pacific Ocean…located approximately 195 NM south of Nadi, Fiji. Sustained winds are near 95 knots, with gusts to near 115 knots. Tropical cyclone Evan will be gradually losing strength from here on out. Here's the JTWC graphical track map, along with a satellite image. 

North and South Indian Oceans:  There are no active tropical cyclones

Interesting:   Climate scientists at the University of Massachusetts Amherst and in England report the first conclusive evidence that Arctic hurricanes, also known as polar lows, play a significant role in driving ocean water circulation and climate. Though it seems like an oxymoron, Arctic hurricanes happen, complete with a central "eye," extreme low barometric pressure and towering 30-foot waves that can sink small ships and coat metal platforms with thick ice, threatening oil and gas exploration.

Now climate scientists at the University of Massachusetts Amherst and in England report the first conclusive evidence that Arctic hurricanes, also known as polar lows, play a significant role in driving ocean water circulation and climate. Results point to potentially cooler conditions in Europe and North America in the 21st century than other models predict.

Geoscientist Alan Condron at UMass Amherst and Ian Renfrew at the University of East Anglia, U.K., write in the current issue of Nature Geoscience that every year thousands of these strong cyclones or polar lows occur over Arctic regions in the North Atlantic, but none are simulated by the latest climate prediction models, which makes it difficult to reliably forecast climate change in Europe and North America over the next couple of decades.

"Before polar lows were first seen by satellites, sailors frequently returned from the Arctic seas with stories of encounters with fierce storms that seemed to appear out of nowhere," says Condron, a physical oceanographer. "Because of their small size, these storms were often missing from their weather charts, but they are still capable of producing hurricane-force winds and waves over 36 feet."

He and Renfrew say that despite the fact that literally thousands of polar lows occur over the Arctic region of the North Atlantic ocean every year, none are simulated by even the most sophisticated climate models. To understand the importance of these storms on climate, Condron and Renfrew therefore turned to a new, state-of-the-art climate model to simulate the high wind speeds associated with these "missing" storms.

"By using higher resolution modeling we can more accurately simulate the high wind speeds and influence of polar lows on the ocean," Condron says. "The lower-resolution models currently used to make climate predictions very much miss the level of detail required to accurately simulate these storms."

He and Renfrew find that by removing heat from the ocean, polar lows influence the sinking of the very dense cold water in the North Atlantic that drives the large-scale ocean circulation or "conveyer belt" that is known as the thermohaline circulation. It transports heat to Europe and North America.

"By simulating polar lows, we find that the area of the ocean that becomes denser and sinks each year increases and causes the amount of heat being transported towards Europe to intensify," Condron points out.

"The fact that climate models are not simulating these storms is a real problem," he adds, "because these models will wrongly predict how much heat is being moving northward towards the poles. This will make it very difficult to reliably predict how the climate of Europe and North America will change in the near future."

Condron also notes that other research groups have found that the number of polar lows might decrease in the next 20 to 50 years. "If this is true, we could expect to see an accompanying weakening of the thermohaline circulation that might be able to offset some of the warming predicted for Europe and North America in the near future."